package com.sky.service.impl;

import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.entity.ShoppingCart;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.mapper.ShoppingCartMapper;
import com.sky.service.ShoppingCartService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.List;


@Service
@Slf4j
public class ShoppingCartServiceImpl implements ShoppingCartService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;

    @Autowired
    private DishMapper dishMapper;

    @Autowired
    private SetmealMapper setmealMapper;

    /*
     * 添加购物车
     */
    public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        //判断当前的加入到购物车中的商品是否已经存在了
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);

        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        //如果已经存在了，只需要将数量加 1
        if(list != null && list.size() > 0) {
            ShoppingCart cart = list.get(0);
            cart.setNumber(cart.getNumber() + 1);   //update shopping_cart set number = ? where id = ?
            shoppingCartMapper.updateNumberById(cart);
        }else {
            //如果不存在，需要插入一条购物车数据

            //判断本次添加到购物车的商品是菜品还是套餐
            Long dishId = shoppingCartDTO.getDishId();
            if(dishId != null) {
                //本次添加到购物车的是菜品
                Dish dish = dishMapper.getById(dishId);
                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());
            }else {
                //本次添加到购物车的是套餐
                Long setmealId = shoppingCartDTO.getSetmealId();

                Setmeal setmeal = setmealMapper.getById(setmealId);
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());
            shoppingCartMapper.insert(shoppingCart);
        }

    }

    /*
     * 查看购物车，根据当前登录用户的id来查询购物车数据
     */
    public List<ShoppingCart> showShoppingCart() {
        return shoppingCartMapper.list(ShoppingCart.builder().userId(BaseContext.getCurrentId()).build());
    }

    /*
     * 清空购物车
     */
    public void cleanShoppingCart() {
        shoppingCartMapper.deleteByUserId(BaseContext.getCurrentId());
    }

    /*
     * 删除购物车中一个商品
     */
    public void delete(ShoppingCartDTO shoppingCartDTO) {

        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);

        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        ShoppingCart cart = list.get(0);
        //判断要删除的商品的数量是否大于1
        if ( cart.getNumber() > 1){
            //商品数量大于1，则数量减一
            cart.setNumber(cart.getNumber() - 1);
            shoppingCartMapper.updateNumberById(cart);
        }else {
            //商品数量等于1，直接删除商品
            shoppingCartMapper.delete(cart);
        }


    }
}
